Each day more than 200,000 United States Postal Service (USPS) carriers deliver mail to approximately 100 million individual domestic addresses. Mail generally consists of three broad types of items, namely letters, flat mail that is larger than letter mail, and parcels. Before a carrier begins to walk through or drive through his or her delivery route, it is the carrier""s responsibility to put all of this mail into an appropriate sequence for efficient delivery.
Under the present USPS procedure, the carrier assembles at least three sequenced stacks of mail, including letters, flats (including enveloped and non-enveloped magazines), and parcels. The carrier may also have one or more additional sequenced stacks, e.g., presorted mass-mail items to be delivered to many or all of the stops on the delivery route. Thus, at each delivery stop the carrier selects the items for that address from each of the various stacks and puts them all into the postal patron""s mailbox. This sorting and shuffling through various stacks of mail is time consuming, inefficient, and consequently expensive to the USPS.
Preliminary tests by the USPS indicate significant potential savings in carrier delivery time if all of the mail pieces for each stop are consolidated into a single package before the carrier begins delivery activities. However, with current mail sorting procedures and the mail-casing equipment now available to the carriers, the additional time required for the carrier to pre-consolidate the mail into individual packages essentially negates the potential savings in delivery time.
More efficient procedures and equipment can be deployed within the post office to make the operation more efficient, thus saving substantial amounts of time and money, by making use of a different sorting system and method as described herein. The current mail case into which the carrier pre-sequences the mail is shown in FIG. 1 as mail case 20. Mail case 20 is not ergonomically well designed to accommodate letters and flats together, nor highly suitable to facilitate expeditious containerizing most or all of each patron""s mail for efficient delivery.
Two significant problems have been observed. Dividers 21 between stops in existing USPS mail cases are relatively rigid, and they cannot conveniently be repositioned during a sort. If a particular patron gets an excessive amount of mail on a given day, the carrier removes part or all of it temporarily. The carrier then must reconsolidate that patron""s mail at the end of the casing operation. Also, as the slot fills, it becomes increasingly difficult to case additional mail into that slot. A more flexible partition between slots would help to remedy both of these shortcomings.
The slots are generally too small to accommodate flats without folding them over as shown in FIG. 1 (folded flat 22). This folding operation is time-consuming and thus costly, and it tends to fill the slot prematurely. In some cases the mail cannot be folded without incurring damage. In this case it must be handled separately, incurring additional handling time and associated labor cost. Larger slots eliminate some of this additional handling effort, but wastes space.
For efficient delivery, all of the mail for each postal patron should be individually containerized or wrapped. To accomplish this with the existing case 20, the contents from each slot must be removed and packaged one stop at a time. With the existing USPS case design, the time required to package each patron""s mail stop-by-stop exceeds the resulting time savings along the delivery route.
The USPS has attempted a system wherein a grocery store-style frame holds a horizontal stack of plastic bags. One bag is torn off the pad and made ready for filling by stretching it open on the frame, while the remaining bags remain on the pad in a closed or completely collapsed (flat) condition. In pulling down the mail from the slots in the case, the postal carrier takes mail from one slot, puts it in a bag, removes the bag from the frame and puts it in a flats tub or letter tray, generally in delivery order. This exposes the next bag on the frame for the mail in the next case slot corresponding to a delivery address. This process makes use of bags to keep mail for a single destination together, but requires several steps and is thus labor intensive. The pull-down process is carried out one destination at a time.
A newly designed mail case is hereby proposed. It facilitates sequence-sorting various types of mail together into individual bags that each represent unique delivery points. The mail case uses multi-bag inserts so that the bags for several stops can be set up quickly for sorting. At the end of the sorting operation, the entire insert or a portion of it may be pulled down from the case as a single unit to maintain the established delivery point sequence. This eliminates the carrier""s need to find separation points or to combine selections from multiple sequenced stacks of mail during the subsequent delivery operation. This results in a dramatic improvement in delivery efficiency. Flexible bag walls allow mail to randomly overfill mail slots that receive greater than the standard volume of mail. This overfilling feature improves efficiency while maintaining slot density.
The invention also provides a more efficient method for sorting a batch of mail to a set of addresses. Such a method includes the steps of: (a) determining the destination address of a mail piece, such as by human review or machine scanning; (b) placing the mail piece in a flexible-walled bag that is one of a row of bags associated with the set of addresses; and (c) repeating steps (a) and (b) until all or substantially all mail in the batch for which an address can be determined has been placed within a bag. In a preferred embodiment, the mail pieces are letters, flats, or parcels, and the bags are accordingly configured as rectangular thin-walled bags, preferably of plastic, with elongated, straight mouths disposed side-by-side to form a rectangular group of bags, or a multi-bag. Following steps (a)-(c), the invention preferably further includes steps of (d) removing groups of bags simultaneously from the rack for placement in a carrying container such as a postal tub or delivery satchel, and then disconnecting the bags for quick and efficient delivery. In this manner, the invention provides for simultaneous bagging and sorting of flat mail, and optionally further permits a group of bags to be pulled-down from the sorting case in order, instead of one address at a time pull-down as presently practiced by the U.S. Postal Service.
A storage device for use in such a method preferably includes a series of flexible, thin-walled bags disposed side by side such that mouths of the bags face a common direction and form a row. The side edges of the mouth of each bag may be integrally bonded (as by fusing or adhesive) to the edges of the mouths of adjoining bags in the widthwise direction of the device to prevent inadvertent insertion of mail between adjacent bags. However, when a case provided with a bag tensioning mechanism is employed, the tension applied to the bags is often sufficient to prevent this, and the bag mouths need not be bonded. The bags are also preferably united by at least one, preferably two reinforcing strips extending in the lengthwise direction of the device. The strips may be formed integrally as part of the multi-bag, or may have suitable means for mounting the series of bags thereon. Preferably a pair of the reinforcing strips are disposed along the top corners of the device on either side of the row of the mouths of the bags. These strips in combination with the means for mounting the bags to the strips should have sufficient strength so that the multi-bag can be manually handled without causing individual bags to separate, yet permit separation of individual bags at the appropriate time, as described hereafter. The strips may also have means thereon for removably securing the storage device to a supporting frame so that the mouths of the bags remain open as items are placed into the bags through the mouths, the strips acting to facilitate loading of the bags into the case.
The storage device of this invention may optionally provide perforations near the mouth of each bag allowing the bag to be torn off. In such a case, the postal carrier can use the storage device directly as a delivery device, replacing the traditional postal satchel into which loose or rubber-banded bundles of mail are placed. To deliver mail, the carrier carries the device, assisted if needed by handles or a strap provided for that purpose. To deliver mail, the carrier walks or drives his or her route and tears off one bag per delivery address, greatly speeding the delivery process.
According to a preferred form of the invention, the multi-bag comprises a series of flexible walled bags disposed side by side such that mouths of the bags face a common direction and form a row, giving the multi-bag a generally rectangular shape when unfilled and stretched to a taut condition. Side edges of each bag near the mouth of each bag may be integrally bonded to the edges of the mouths of adjoining bags. A pair of reinforcing strips extending in the lengthwise direction of the multi-bag along opposite upper corners of the multi-bag. Suitable means are provided for attaching the strips to the multi-bag so that the strips unite the multi-bag, and the strips and attaching means may have sufficient strength so that the multi-bag can be handled without coming apart, especially when loaded, for example, with up to about 20 pounds of mail pieces or other items. The attaching means may take a variety of forms as described hereafter including applied adhesive, adhesive tape double or single sided, weld(s), mechanical interlocking of bag surfaces, and fasteners.
A preferred sorting case of the invention suitable for use with such multi-bag storage devices has suitable means for mounting the storage devices therein with the bag mouths facing outwardly, means for tensioning the bags to hold the bag mouths open during loading of items therein and for relaxing the bags to facilitate mounting in and removal from the case, and means for locking the bags in a taut condition during loading. The locking mechanism according to this embodiment preferably includes a movable shelf that moves relative to a stationary shelf to pull the bags taut from opposite sides, and a mechanism for releasably clamping opposite sides of each multi-bag to lock them into position during loading, so that the bags do not work loose from the case during mail sorting.
As discussed above, a postal sorting case includes a plurality of slots defined by dividing walls, each slot being labeled for sorting of mail to a specific address. Regardless of the specific construction of the sorting case, an essential principle of the invention is the use of slot dividing walls made of a flexible or compliant material which permits random overfilling of certain slots while maintaining the same overall slot density. This could be accomplished using, for example, flexible pouches or bendable dividers, without the multi-bag features. These and other aspects of the invention are described in the detailed description that follows.